When video data is transmitted in real-time, it is desirable to send as little data as possible. Many conventional video compression standards use the technique of motion estimation in conjunction with a DCT (Discrete Cosine Transform). Although the DCT itself does not result in any reduction, it converts the input video into a form where redundancy can be easily detected. Data transmission can then take advantage of the temporal domain redundancies in the video bit-stream.
Unfortunately, although conventional motion estimation aids in bit compression of video data, it is extremely computation intensive. Thus, compromises are inevitable--and many conventional systems settle for a somewhat less accurate motion vector in exchange for a lower consumption of computing resources. FIG. 2 shows a conventional method of motion estimation. In this conventional method, a search block 230 is moved to all vertical and horizontal displacements of a reference block, on a pel-by-pel basis, to determine what movement has occurred between the reference block and the search block.